Hybrid integrated circuit device, and method for fabricating the same, and electronic device

ABSTRACT

A hybrid integrated circuit device having high mount reliability comprises a module substrate which is a ceramic wiring substrate, a plurality of electronic component parts laid out on the main surface of the module substrate, a plurality of electrode terminals laid out on the rear surface of the module substrate, and a cap which is fixed to the module substrate to cover the main surface of the module substrate. The electrode terminals include a plurality of electrode terminals which are aligned along the edges of the module substrate and power voltage supply terminals which are located inner than these electrode terminals. The electrode terminals aligned along the substrate edges are coated, at least in their portions close to the substrate edge, with a protection film having a thickness of several tens micrometers or less. Connection reinforcing terminals consist of a plurality of divided terminals which are independent of each other, and are ground terminals.

TECHNICAL FIELD

The present invention relates to a hybrid integrated circuit device andan electronic device which incorporates the hybrid integrated circuitdevice, and particularly to a technique which is applied effectively toa high-frequency power amplifier module, which is used for thetransmitter of a wireless communication unit such as a cellulartelephone unit, and to a wireless communication unit (portable telephoneunit) which incorporates the high-frequency power amplifier module.

BACKGROUND ART

One known hybrid integrated circuit device is a high-frequency poweramplifier module which is used for the wireless communication section ofmobile communication units such as automobile telephone units andportable telephone units.

Japanese Patent Unexamined Publications No. Hei 8(1996)-148597 and No.Hei 9(1997)-18145 describe hybrid integrated circuit devices.

The patent publication No. Hei 8(1996)-148597 describes semiconductormodules of LGA (Land Grid Array) type.

The patent publication No. Hei 9(1997)-18145 describes a technique forpreventing cracks from occurring in a ceramic multi-layer substrate,from its positions at the rim of electrode terminals into the inside ofsubstrate, based on the fabrication process, prior to the annealingprocess, of forming the electrode terminals on the surface of alaminated green sheet, and thereafter laminating a patterned greed sheet(a greed sheet with the formation, at its positions confronting theelectrode terminals, of through-holes having a diameter smaller than theelectrode terminals) on the laminated green sheet while leaving smallareas of electrode terminals.

The high-frequency power amplifier module used for the portabletelephone unit is amid the technical progress in terms of size reductionand performance upgrading. A high-frequency power amplifier module ismounted on a setup board (circuit board) by soldering the electrodeterminals (connection terminals), which are located at the bottom edgeof module, to the lands on the surface of setup board. Specifically, thehigh-frequency power amplifier module is placed by being positioned onthe setup board, and solder which has been already applied to the landsof setup board is heated (to reflow) so that the module terminals aresoldered to the lands and fixed on the setup board.

In recent years, there is a growing trend of the LGA structure adoptedfor the high-frequency power amplifier module to meet the demands ofsize reduction, performance upgrading, increasing pins, and mount areareduction.

The inventors of the present invention have confirmed the followingprograms in regard to the LGA structure of the high-frequency poweramplifier module designed for the portable telephone unit.

FIG. 24 is a schematic diagram explaining the faulty setup of ahigh-frequency power amplifier module revealed by the study conducted bythe inventors prior to the present invention. A high-frequency poweramplifier module has its substrate 1 made of a multi-layer ceramicwiring substrate, and electrode terminals 2 are formed on the rearsurface to align along the edge of substrate.

The high-frequency power amplifier module is mounted (fixed) on a setupboard 3 by overlapping the electrode terminals 2 on the lands (footprint) 4 formed on the upper surface of the board 3, and fusing (toreflow) solder 5 which has been already applied to the lands 4 and thesurface of electrode terminals 2 so that the electrode terminals 2 arefixed by soldering to the lands 4. Although the figure shows only oneelectrode terminal 2, all electrode terminals formed along the edgesaround the bottom of the module substrate 1 are connected to the landsto complete the mounting of module.

However, it was found that this high-frequency power amplifier moduledevelops cracks 6 in the module substrate 1 as shown in FIG. 24,resulting in a degraded reliability of the high-frequency poweramplifier module.

The electrode terminals 2 and solder 5 are both metallic and thereforehave a greater bonding strength than the bonding strength between theceramic module substrate 1 and the electrode terminals 2. In addition,the ceramic module substrate 1 has a thermal expansivity coefficient ofaround 7×10⁻⁶/° C., while the setup board 3 is a glass-epoxy board (madeof glass fiber and epoxy resin) having a thermal expansivity coefficientof around 16×10⁻⁶/° C., exhibiting a significant difference.

In consequence, due to the stress caused by the difference of thermalexpansion and contraction between the setup board 3 and electrodeterminals 2, the relatively fragile module substrate 1 is liable todevelop a crack 6. The crack 6 starts at a position (point) subjected toa large stress and advances deep into the module substrate 1 as shown inFIG. 24. The dashed-line arrows in the figure indicate the direction ofstress which causes the crack. The development of crack 6 candeteriorate the reliability of high-frequency power amplifier module.

The above-mentioned patent publication No. Hei 9(1997)-18145 describes,as mentioned above, a technique for preventing cracks from occurring ina ceramic multi-layer substrate, from its positions at the rim ofelectrode terminals into the inside of substrate, based on thefabrication process, prior to the annealing process, of forming theelectrode terminals on the surface of a laminated green sheet, andthereafter laminating a patterned greed sheet (a greed sheet with theformation, at its positions nearby the electrode terminals, ofthrough-holes having a diameter smaller than the electrode terminals) onthe laminated green sheet while leaving small areas of electrodeterminals, however, it does not describe in detail the mechanism ofcrack development.

The inventors of the present invention have found a fact that cracks areliable to occur in the module substrate at its positions of theelectrode terminals, at their positions close to the substrate edge,which are located close to the edges of both ends or sides of the modulesubstrate. Namely, the development of cracks, which are liable atpositions of the electrode terminals 2, in their portions close to thesubstrate edge, which are located close to the edges of the modulesubstrate 1, can be alleviated by coating these portions at least with aprotection film.

In regard to the above-mentioned conventional technique, i.e.,overlapping of a green sheet, with through-holes which are smaller indiameter than the electrode terminals being formed, at positionsconfronting the electrode terminals, and subsequent annealing, it isnecessary for the sake preventing the damage in the edge section to makewide edge section where the through-holes are narrowest, resulting in alarger green sheet and thus an increased size of high-frequency poweramplifier module.

Moreover, the green sheet with through-holes overlaped on another greensheet necessitates marginal dimensions so as to ensure the covering ofthe rim of electrode terminals, results in a much larger green sheet.

Therefore, the conventional technique based on the overlapping of greensheet causes an increased dimensions of green sheet, which precludes thereduction in the size of module board and thus the size ofhigh-frequency power amplifier module.

A green sheet having through-holes needs to be thicker to some extentfor the sake of damage-free treatment, and the use of extra green sheetmaterial results in an increased cost of the module.

It is an object of the present invention to provide a hybrid integratedcircuit device having high mounting reliability, and an electronicdevice which incorporates this hybrid integrated circuit device.

Another object of the present invention is to provide a hybridintegrated circuit device having high mounting reliability and havingpotential of manufacturing cost reduction, and an electronic devicewhich incorporates this hybrid integrated circuit device.

Still another object of the present invention is to provide ahigh-frequency power amplifier module having high mounting reliability,and a wireless communication unit which incorporates this high-frequencypower amplifier module.

Still another object of the present invention is to provide ahigh-frequency power amplifier module having high mounting reliabilityand having potential of manufacturing cost reduction, and a wirelesscommunication unit which incorporates this high-frequency poweramplifier module.

These and other objects and novel features of the present invention willbecome apparent from the following description and attached drawings.

DISCLOSURE OF THE INVENTION

Among the affairs of the present invention disclosed in thisspecification, representatives are briefed as follows.

(1) The inventive hybrid integrated circuit device is structured asfollows. It comprises a module substrate which is a rectangular ceramicwiring substrate, a plurality of electronic component parts laid out onthe main surface of the module substrate, a plurality of electrodeterminals laid out on the rear surface of the module substrate, and ametallic cap which is fixed to the module substrate to cover the mainsurface of the module substrate. The electrode terminals include,aplurality of electrode terminals which are aligned along the edges ofmodule substrate and power voltage supply terminals which are locatedinner than these electrode terminals. The electrode terminals alignedalong the module substrate edges are coated, at least in their portionsclose to the substrate edge, with a protection film. A plurality ofsemiconductor amplifying elements are connected tandem on the modulesubstrate to form a high-frequency power amplifier module. Theprotection film, which is a glass layer or solder resist layer, isformed by printing to have a thickness of several tens micrometers orless.

The metallic cap is fixed to the module substrate by means of resilienthooks which are part of the cap and hook stoppers which are provided onthe module substrate. Four sets of hook and hook stopper are provided atthe four corners of the cap and module substrate.

The module substrate has its four corners cut away inwardly, in whichportions are disposed the hook stoppers made of conductor which latchwith the hooks of the cap. The cap retains the rectangular profile.Further provided at the four corners of the module substrate are groundterminals, which are connected electrically to the conductive hookstoppers. The hooks extend downward to reach or nearly reach the rearsurface of the module substrate.

The connection reinforcing terminals consist of a plurality of dividedterminals which are independent of each other. For example, a pluralityof power voltage supply terminals are aligned along one side of themodule substrate and also along the direction orthogonal to this side.

(2) The hybrid integrated circuit device is fabricated based on thefollowing method. The hybrid integrated circuit device comprises amodule substrate of a ceramic wiring substrate, a plurality ofelectronic component parts laid out on the main surface of the modulesubstrate, a plurality of electrode terminals laid out on the rearsurface of the module substrate, and a cap which is fixed to the modulesubstrate to cover the main surface of the module substrate. The methodincludes a step of overlapping a plurality of green sheets, with wiringpatterns being formed thereon, and pressing the sheets to make alaminated green sheet having an electrode terminal section on the rearsurface, a step of printing paste to form a protective overlay so thatterminals located close to the edges of laminated green sheet arecoated, at least in their portions close to the edge of laminated greensheet, with the protective overlay, and a step of annealing thelaminated green sheet, electrode terminal section and protection film tocomplete a module substrate having electrode terminals which arepartially coated with a protection film.

(3) The inventive electronic device is structured as follows. Itcomprises a setup board having lands for fixing a hybrid integratedcircuit device on the main surface, and a high-frequency power amplifiermodule having its electrode terminals connected electrically bysoldering to the lands. The hybrid integrated circuit device comprises amodule substrate which is a rectangular ceramic wiring substrate, aplurality of electronic component parts laid out on the main surface ofthe module substrate, a plurality of electrode terminals laid out on therear surface of the module substrate, and a rectangular metallic capwhich is fixed to the module substrate to cover the main surface of themodule substrate. Ground terminals are provided at the four corners ofthe module substrate. The metallic cap is fixed to the module substrateby means of resilient hooks which are part of the cap and hook stopperswhich are provided on the module substrate. The hooks are fixed bysoldering to the lands formed on the main surface of the setup board.The module substrate has its four corners cut away inwardly, in whichportion are provided the hook stoppers. The cap has a rectangularprofile. The electrode terminals include a plurality of electrodeterminals which are aligned along the edges of module substrate and aplurality of power voltage supply terminals which are located inner thanthese electrode terminals. The power voltage supply terminals are fixedby soldering to the lands formed on the main surface of the setup board.The electrode terminals aligned along the edges of module board arecoated, at least in their portions close to the board edge, with aprotection film having a thickness of several tens micrometers or less.The hybrid integrated circuit device is a high-frequency power amplifiermodule, which constitutes a wireless communication unit.

The high-frequency power amplifier module (hybrid integrated circuitdevice) arranged as described in the above item (1) attains thefollowing effectiveness.

(a) In the high-frequency power amplifier module (hybrid integratedcircuit device), the electrode terminals of LGA structure aligned alongthe edges of module substrate are coated in their portions close to thesubstrate edge with a protection film, and accordingly even if therearises a thermal stress between the electrode terminals and the modulesubstrate when the module is mounted on the setup board of portabletelephone unit, the module substrate is prevented from cracking in itsterminal border portion close to the substrate edge, and thus thepackage interior is free from penetration of water or the like throughcracks, whereby the high-frequency power amplifier module and portabletelephone unit are enhanced in reliability and life span.

(b) The protection film which is made from printed paste can be as thinas several tens micrometers or less, enabling the reduction of thicknessof the module substrate and also the reduction of manufacturing costowing to the reduced consumption of paste. In consequence, the reductionof manufacturing cost of the portable telephone unit can be attained.

(c) The protection film which is made from printed paste is thinner thana green sheet having through-holes, allowing the size reduction of themodule substrate and thus the size reduction of the high-frequency poweramplifier module. In consequence, the size reduction of the portabletelephone unit can be attained.

(d) The high-frequency power amplifier module is fixed to the setupboard by additional use of the power voltage supply terminals besidesthe electrode terminals, whereby the high-frequency power amplifiermodule is enhanced in mount rigidity. The power voltage supply terminalsalso serve as ground terminals, stabilizing the ground voltage in everycircuit section of the high-frequency power amplifier module, wherebythe stable operation can be expected. In consequence, the portabletelephone unit operates stably, enabling the user to have comfortablecommunication.

(e) The power voltage supply terminals are aligned along the long sideand short side of the module substrate. On this account, thehigh-frequency power amplifier module is mounted by being placeduprightly on multiple reflowing molten solder spots so that the modulesubstrate is mounted by being spaced out evenly from the setup board,whereby power supply properties such as efficiency can be stabilized. Inconsequence, the portable telephone unit operates stably, enabling theuser to have comfortable communication.

(f) The module substrate has the formation cut-away portions at bothends of long sides, in which portions the cap has its hooks latchingwith the hook stoppers of the module substrate, thereby building apackage, and hook support arms have their solder fillet jutting out aslittle as 0.3 μm. Accordingly, the mount area can be virtually withinthe area defined by the profile of cap, enabling the reduction of mountarea. In consequence, the size reduction of the portable telephone unitcan be attained.

(g) The hook support arms extend downward to reach or nearly reach therear surface of the module substrate, and accordingly the high-frequencypower amplifier module, when mounted on the setup board by soldering, isconnected electrically by solder to the grounding lands, whereby thehigh-frequency power amplifier module is enhanced in mount rigidity andensured in electrical grounding. In consequence, the portable telephoneunit operates stably, enabling the user to have comfortablecommunication.

(h) The provision of ground terminals at the four corners of therectangular module substrate facilitates the layout design of externalterminals including the signal terminals and power terminals of thehigh-frequency power amplifier module, and it also facilitates thelayout of wiring lines on the setup board which mounts the module.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional diagram of a high-frequency poweramplifier module based on an embodiment (embodiment 1) of thisinvention;

FIG. 2 is a perspective view of the high-frequency power amplifiermodule of the embodiment 1;

FIG. 3 is a plan view of the bottom of the module substrate of thehigh-frequency power amplifier module of the embodiment 1;

FIG. 4 is a cross-sectional diagram showing part of the high-frequencypower amplifier module of the embodiment 1;

FIG. 5 is a schematic cross-sectional diagram showing part of the modulesubstrate;

FIG. 6 is a flowchart showing the fabrication process of thehigh-frequency power amplifier module of the embodiment 1;

FIG. 7 is a schematic cross-sectional diagram showing the laminatedgreen sheet, with wiring lines and electrode terminals being formedthereon, in the fabrication process of the high-frequency poweramplifier module of the embodiment 1;

FIG. 8 is a schematic cross-sectional diagram showing the modulesubstrate, with the electrode terminals being coated in their outer edgesection with a protection film, in the fabrication process of thehigh-frequency power amplifier module of the embodiment 1;

FIG. 9 is a schematic diagram showing the formation of the protectionfilm;

FIG. 10 is a schematic cross-sectional diagram showing the modulesubstrate, with electronic component parts being mounted thereon, in thefabrication process of the high-frequency power amplifier module of theembodiment 1;

FIG. 11 is a schematic cross-sectional diagram showing the modulesubstrate, with the semiconductor chip and wiring lines being coatedwith resin, in the fabrication process of the high-frequency poweramplifier module of the embodiment 1;

FIG. 12 is a schematic cross-sectional diagram showing the mount stateof the high-frequency power amplifier module on the setup board of aportable telephone unit based on the embodiment 1;

FIG. 13 is a cross-sectional diagram showing part of the mount state ofthe high-frequency power amplifier module;

FIG. 14 is a cross-sectional diagram showing part of the mount state ofthe electrode terminal section of the high-frequency power amplifiermodule;

FIG. 15 is a plan view showing part of the layout of lands on the setupboard;

FIG. 16 is an equivalent circuit diagram of the high-frequency poweramplifier module;

FIG. 17 is a block diagram showing the functional arrangement of theportable telephone unit;

FIG. 18 is a schematic cross-sectional diagram of a high-frequency poweramplifier module based on another embodiment (embodiment 2) of thisinvention;

FIG. 19 is-a plan view of the bottom of the module substrate of thehigh-frequency power amplifier module of the embodiment 2;

FIG. 20 is a cross-sectional diagram showing partially the connection ofan electrode terminal to the substrate of the high-frequency poweramplifier module of the embodiment 2;

FIG. 21 is a plan view of the bottom of a high-frequency power amplifiermodule based on still another embodiment (embodiment 3) of thisinvention;

FIG. 22 is a perspective view of a high-frequency power amplifier modulebased on still another embodiment (embodiment 4) of this invention;

FIG. 23 is a cross-sectional diagram showing part of the high-frequencypower amplifier module of the embodiment 4; and

FIG. 24 is a schematic diagram explaining the faulty mounting of ahigh-frequency power amplifier module revealed by the study conducted bythe inventors prior to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The embodiments of this invention will be explained in detail withreference to the drawings. Throughout the figures, items having the samefunctions are referred to by the common symbols, and explanation thereofis not repeated.

Embodiment 1

FIG. 1 through FIG. 17 are diagrams pertaining to a high-frequency poweramplifier module and a portable telephone unit which incorporates themodule based on an embodiment (embodiment 1) of this invention. Amongthe figures, FIG. 1 through FIG. 11 are of the high-frequency poweramplifier module, and FIG. 12 through FIG. 17 are of the portabletelephone unit.

Explained in this embodiment are a high-frequency power amplifiermodule, as hybrid integrated circuit device, having amplifying systemsfor GSM (Global System for Mobile Communication) and DCS (DigitalCellular System), and a wireless communication unit which incorporatesthe high-frequency power amplifier module.

The high-frequency power amplifier module 10 has an external appearanceof a flat cuboid as shown in FIG. 1 and FIG. 2.

The high-frequency power amplifier module 10 is structured to have amodule substrate 11 which is a ceramic wiring substrate and a cap 12which is put on one surface (main surface) of the module substrate 11,thereby building a flat cuboidal package 13.

The cap 12, which is made of metal, has the electromagnetic shieldingeffect. The cap 12 is formed by bending a metallic sheet to have a shapeof rectangular box with side walls 30 as shown in FIG. 2. Both long sideend sections of the cap 12 extend downwardly to form hook support arms31. The hook support arms 31 have their end section formed to becomehooks 32 which protrude inwardly. The hook support arm 31 causes thehook 32 to latch resiliently with a stopper 33 which is a steppedportion of the module substrate 11 as shown in FIG. 4. The modulesubstrate 11 has its four corners cut away inwardly to allow rooms forthe hook support arms 31 as shown in FIG. 3. This cut-away portion 34has a step in the thickness direction, which becomes the stopper 33 tolatch with the hook 32 as shown in FIG. 4.

A conductor layer 35 is formed to extend from the stopper 33 to the rearsurface of the module substrate 11. The conductor layers 35, in theirportion running on the rear surface of module substrate 11 becometerminals 35 a, which can be used as connection terminals for fixing thehigh-frequency power amplifier module 10 to the setup-board and also asground terminals. With grounding lands 37 being formed on the mainsurface 6 f setup board 36 in correspondence to the terminals 35 a, thecap 12 used for electromagnetic shielding can be connected to the groundof the setup board by way of the hooks 32 and conductor layers 35. Thehook support arm 31 extends to reach or nearly reach the rear surface ofthe module substrate 11 as shown in FIG. 4, and the high-frequency poweramplifier module 10, when it is mounted on the setup board 36, isconnected electrically by solder 38 to the grounding lands 37, wherebythe high-frequency power amplifier module 10 is enhanced in mountrigidity and ensured in electrical grounding.

The provision of ground terminals at the four corners of the rectangularmodule substrate 11 facilitates the layout design of external terminalsincluding signal terminals and power terminals of the high-frequencypower amplifier module 10, and it also facilitates the layout of wiringlines on the setup board which mounts the module 10.

The module substrate 11 is a ceramic wiring substrate which is formed,for example, by laminating glass ceramics and annealing at a lowtemperature. The module substrate 11 mounts chip resistors 15, chipcapacitors 16, etc. on its main surface as shown in FIG. 1. The modulesubstrate 11 has a recessed area on the main surface, on the bottom ofwhich is mounted a semiconductor chip 17 which constitutes semiconductoramplifying elements. The semiconductor chip 17 has its electrode pins(not shown) connected electrically by wires 18 to wiring lines (notshown) formed on the main surface of the module substrate 11. Thesemiconductor chip 17 and wires 18 are coated with insulative resin 19so as to be durable against humidity.

The module substrate 11 has on its rear surface the formation of aplurality of electrode terminals 20 aligned along the edges of substrateand a plurality of power voltage supply terminals 21 arranged in theinner area as shown in FIG. 1 and FIG. 3. The electrode terminals 20 andpower voltage supply terminals 21, which are intended for surfacemounting of LGA structure, are made from a conductor layer formed on therear surface of the module substrate 11.

The high-frequency power amplifier module 10 is fixed to the setup boardby additional use of the power voltage supply terminals 21 besides theelectrode terminals 20, whereby the high-frequency power amplifiermodule 10 is enhanced in mount rigidity. The power voltage supplyterminals 21 also serve as ground terminals, stabilizing the groundvoltage in every circuit section of the high-frequency power amplifiermodule 10, whereby the stable operation of the module can be expected.

The chip resistors 15, chip capacitors 16 and semiconductor chip 17 arefixed by being connected to electrode pads 22 and mount pads 23 whichare formed on the main surface of the module substrate 11. The electrodepads 22 and mount pads 23 are made from matalized conductive layers. Theportion of module substrate where the semiconductor chip 17 is mountedhas the formation of a plurality of through-holes (via holes), which arefilled with conductor 24. The conductor 24 connects electrically themount pads 23 to the power voltage supply terminals 21. The powervoltage supply terminals 21 are occasionally used as ground terminals tobe connected electrically to the ground pins of semiconductor chip 17.Namely, the power voltage supply terminals 21 can be entirely groundterminals, or can be partially ground terminals and partially connectionreinforcing terminals.

The power voltage supply terminals 21 are arranged along the long andshort sides of the module substrate 11. In case there is only one powervoltage supply terminal 21, the module substrate 11, i.e., thehigh-frequency power amplifier module 10, when placed on molten solderat the time of mounting, can possibly incline with respect to the setupboard. Therefore, in the embodiment 1, solder 38 is fused on thehorizontally placed setup board 36, while using the power voltage supplyterminals 21 arranged along the long and short sides of the modulesubstrate 11 to support the module substrate 11 (high-frequency poweramplifier module 10) horizontally, thereby preventing the high-frequencypower amplifier module 10 from being fixed aslant with respect to thesetup board, as shown in FIG. 12.

The electrode terminals 20 aligned along the edges of module substrate11 have the following functions. The electrode terminals 20 are numberedfor the purpose of explanation in FIG. 3. Terminals #1, #8, #9, #12,#13, #18, #19, #20 and #24 are non-contact (NC) terminals, #2, #10 and#22 are ground terminals, #3, #4 and #5 are Vdd-GSM terminals, #6 is aVapc-GSM terminal, #7 is a Pout-DCS terminal, #11 is a Pout-GSMterminal, #14 is a Vapc-DCS terminal, #15, #16 and #17 are Vdd-DCSterminals, #21 is a Pin-GSM terminal, and #23 is a Pin-DCS terminal.

As a feature of this invention, the electrode terminals 20 is coated intheir portion close to the module substrate edge with a protection film40 as shown in FIGS. 1, 3, 5 and 14. In FIG. 3, the power voltage supplyterminals 21 and conductor layer 35, which are all conductor, are shownby dashed lines.

The protection film 40 is formed by the following process. Initially, aplurality of green sheets, with wiring patterns being formed thereon,are overlaped, and the sheets are pressed to make a laminated greensheet having an electrode terminal section on the rear surface. Next,paste of glass or solder resist is printed to cover at least the rimsection of electrode terminals, thereby forming a protective overlay.Next, the green sheet, electrode terminal section and protective overlayare treated by the annealing process.

The annealing process causes the laminated green sheet to become amodule substrate, with the electrode terminal section on the surface andprotective overlay of terminal section turning into electrode terminalsand protection film. The paste is printed thinner so that the protectionfilm is made as thin as several tens micrometers or less. Consequently,the consumption of paste is reduced and thus the manufacturing cost ofmodule substrate can be reduced, and a thinner module substrate 11 canbe accomplished.

The print position can be selected arbitrarily based on the design ofscreen pattern, which enables accurate printing of a precise pattern. Inconsequence, the module substrate can be made smaller by the amount ofreduced marginal area for electrode terminals at the substrate edges,and thus the module substrate can be made smaller, and thus thehigh-frequency power amplifier module can be made more compact.

FIG. 9 shows schematically the formation of a protective overlay 48based on screen printing on a laminated green sheet 43, with anelectrode terminal section 47 being formed on its rear surface. Thescreen 42 stretched across the frame 41 is positioned and broughtclosely to the rear surface of laminated green sheet 43, and next theskeg 44 is moved so that paste 45 on the screen 42 is printed on aselected position on the rear surface of laminated green sheet 43 toform a protective overlay 48.

Subsequently, the laminated green sheet 43 inclusive of the electrodeterminal section 47 and protective overlay 48 is treated by theannealing process. The annealing process causes the electrode terminalsection and protective overlay to turn into the electrode terminals 20and protection film 40, and the laminated green sheet 43 becomes amodule substrate 11 as shown in FIG. 5.

FIG. 15 is a plan view of part of the setup board 36 which mounts thehigh-frequency power amplifier module 10. Lands include grounding lands37 located at the four corners of substrate corresponding to theterminals 35 a, terminal lands 49 a, to which the electrode terminals 20are fixed, aligned between the ground lands 37, and lands 49 b to whichthe power voltage supply terminals 21 are fixed. These lands haveapplication of solder on the surface.

Next, the fabrication process of the high-frequency power amplifiermodule 10 of the embodiment 1 will be explained briefly with referenceto the flowchart of FIG. 6. The high-frequency power amplifier module 10is fabricated and shipped through the processing steps as shown by theflowchart of FIG. 6, which include: preparation of laminated green sheet(step 101), printing of protective overlay (step 102), annealing (step103), application of solder to module substrate (step 104), mounting ofparts (step 105), solder reflow (step 106), cleaning (step 107), wireboding (step 108), coating of resin (step 109), baking (step 110),fixing of cap (CAP) (step 111), dicing of module substrate (step 112),selection (step 113), and packing (step 114). The module substrate maybe fabricated for each device, or the module substrate may be dividedinto devices after caps are put on.

The laminated green sheet 43 is made by, for example, overlapping aplurality of dielectric sheets (green sheets) and pressing the sheets asshown in FIG. 7. The figure shows the structure including five greensheets laminated. The diagram corresponds to FIG. 1.

The laminated green sheet 43 has the formation on the rear surfacethereof of a conductor layer 70 which becomes the electrode terminals 20and power voltage supply terminals 21, and has the formation on the mainsurface thereof of another conductor layer 70 which becomes theelectrode pads 22 and mount pads 23 for mounting electronic componentparts. The portion of conductor layer 70 for the electrode terminals 20is called the electrode terminal section 47 as mentioned previously. Inthe area where the semiconductor chip is mounted, the upper first andsecond green sheets are cut away to make a recessed area on thelaminated green sheet 43. This recessed area also has on its bottom theformation of a conductor layer 70: (step 101).

Next, with the laminated green sheet 43 being turned over, theabove-mentioned paste is printed on the rim of electrode terminals 20which are close to the edges of laminated green sheet 43, therebyforming the protective overlay 48: (step 102), and the sheet 43 istreated by annealing: (step 103), and the module substrate 11 having theelectrode terminals 20 and power voltage supply terminals 21 is made asshown in FIG. 8. The electrode terminals 20 are coated in their rimportion close to the edge of module substrate 11 with the protectionfilm 40. The electrode pads 22, mount pads 23 and conductors 24 are alsoformed. Wiring lines of this module substrate 11 have the strip linestructure or micro strip line structure.

Next, solder is applied to the surface of all conductor layers: (step104), electronic component parts including the semiconductor chip 17,chip resistors 15 and chip capacitors 16 are mounted: (step 105), andthe solder is heated to reflow so that the electronic parts areconnected: (step 106).

The module substrate 11 is around 0.8 mm in thickness, 15 mm in widthand 8 mm in length, for example. The thickness of the electrode of theelectrode terminal is about 10 μm. The protection film which partiallycovers the electrode terminals is around several tens micrometers-orless in thickness.

Next, the module substrate is cleaned to wash off flux: (step 107), thesemiconductor chip 17 is connected from its terminals (not shown) towiring lines by conductive wires 18: (step 108), and the semiconductorchip 17 and wires 18 are coated with insulative resin 19: (step 109).

Next, the module substrate is baked to harden the insulative resin 19:(step 110).

Next, caps 12 are put on the module substrate 11: (step 111), and thesubstrate is divided into high-frequency power amplifier modules 10 asshown in FIG. 2: (step 112). Next, the modules 10 are selected in termsof quality: (step 113), and good modules are packed for shipment: (step113).

The following explains an electronic device, i.e., portable telephoneunit (wireless communication unit), which incorporates the inventivehigh-frequency power amplifier module 10. The high-frequency poweramplifier module 10 is mounted on the setup board 36 of the portabletelephone unit (wireless communication unit). FIG. 12 shows thehigh-frequency power amplifier module 10 mounted on the setup board 36.The high-frequency power amplifier module 10 is placed by beingpositioned on the setup board 36 having a land pattern as shown in FIG.15. Solder which has been applied to the surface of lands (37, 49 a and49 b) and terminals (20, 21 and 35 a) is heated to reflow so that themodule is connected to them, and the portable telephone unit as shown inFIG. 12 (only the module setup portion is shown) is completed.

FIG. 13 is a cross-sectional diagram showing the fitting of the hook 32.The conductor layer 35, the hook 32 and the lower end of the hooksupport arm 31 are fixed to the grounding land 37 by solder 38. The hooksupport arm 31 has its solder fillet on its outer surface jutting out aslittle as around 0.3 μm for example. Based on the package structurebuilt by the module substrate 11 and cap 12, with the hooks 3 of caplatching with the hook stoppers 33 of module substrate 11 in thecut-away portions 34 provided at both ends of long side of the modulesubstrate 11, and on the jut-out length of solder fillet as small as 0.3μm, it is possible to lay out the grounding lands 37 in rectangularareas created on the extended lines of the substrate sides. Inconsequence, the size reduction of the setup board 36 of the portabletelephone unit and thus the size reduction of the portable telephoneunit can be attained.

The electrode terminals 20 of LGA structure aligned along the edges ofmodule substrate 11 are coated in their portion close to the substrateedge with the protection film 40 as shown in FIG. 14, and consequentlyeven if there arises a thermal stress between the electrode terminals 20and the module substrate 11, the module substrate 11 is prevented fromdeveloping cracks 6 shown in FIG. 24 in its terminal border portionclose to the substrate edge.

In consequence, the interior of package 13 is free from penetration ofwater or the like through cracks, whereby the high-frequency poweramplifier module 10 is enhanced in reliability and life span.

The high-frequency power amplifier module 10 of the embodiment 1 has acircuit arrangement as shown in FIG. 16, which includes line patternsand electronic component parts including semiconductor amplifyingelements formed and mounted on the module substrate 11.

The high-frequency power amplifier module has an amplifying system “e”for GSM and another amplifying system “f” for DCS. These amplifyingsystems “e” and “f” have the same circuit arrangement and are differentin some of their component parts. The following is the explanation ofamplifying system “e”, which is common to the amplifying system “f”,with its component parts being written in parenthesis.

Among the external electrode terminals of the module, the amplifyingsystem “e” has an input terminal Pin-GSM (Pin-DCS), an output terminalPout-GSM (Pout-DCS), a first reference voltage, i.e., power voltage,terminal Vdd-GSM (Vdd-DCS), a bias voltage terminal Vapc-GSM (Vapc-DCS),and a second reference voltage, i.e., ground voltage, terminal GND(common).

Three amplifying stages are connected tandem between the terminalsPin-GSM (Pin-DCS) and Pout-GSM (Pout-DCS). The first, second and third(last) amplifying stages are transistors Q1, Q2 and Q3 (Q4, Q5 and Q6),respectively.

The transistor of each stage has a control terminal (gate electrode)which receives the input signal or bias voltage to the stage, a firstterminal (drain electrode) which releases the output signal of thestage, and a second terminal (source electrode) which receives thereference voltage (ground voltage) for the stage.

The Pin-GSM (Pin-DCS) is connected to the gate electrode of thetransistor Q1 (Q4) through a matching circuit L1 (L8) The second andthird transistors have their gate electrodes connected to the drainelectrodes of the respective former-stage transistors through matchingcircuits L3 (L10) and L5 (L12), respectively. The last-stage, i.e.,output, transistor Q3 (Q6) has its drain electrode connected to thePout-GSM (Pout-DCS) through a matching circuit L3 (L6).

All transistors Q1, Q2 and Q3 (Q4, Q5 and Q6) have their drainelectrodes connected to the Vdd-GSM (Vdd-DCS) through matching circuitsL2, L4 and L6 (L9, L11 and L13).

All transistors Q1, Q2 and Q3 (Q4, Q5 and Q6) have their gate electrodesconnected to the Vapc-GSM (Vapc-DCS). Arranged on the path between thesegate electrodes and the Vapc-GSM (Vapc-DCS) are bias circuits whichcontrol the bias voltages of the gate electrodes. The bias circuits aremade up of voltage dividing resistors R1-R5 (R6-R10).

The portion of FIG. 16 enclosed by the dashed line is the semiconductorchip (FET chip) 17. The semiconductor chip 17 incorporates thetransistors Q1 and Q2 of the GSM amplifying system “e” and the biasvoltage setting resistors R1, R2, R3, R4 and R5 for the transistors Q1and Q2, and the transistors Q4 and Q5 of the DCS amplifying system “f”and the bias voltage setting resistors R6, R7, R8, R9 and R10 for thetransistors Q4 and Q5. Based on the monolithic structure of theseelements, the high-frequency power amplifier module can be made compactand the manufacturing cost can be reduced.

This high-frequency power amplifier module is built in a portabletelephone unit as shown in FIG. 17. The figure is a block diagram ofpart of a dual-band wireless communication unit, showing a portion froma high-frequency signal processor IC (RF linear) 50 up to an antenna 51.The circuit arrangement is divided into the GSM amplifying system andDCS amplifying system which include a power amplifier (PA) 58 a andpower amplifier (PA) 58 b, respectively.

The antenna 51 is connected to the antenna terminal of the antennatransmission/reception switching device 52. The antennatransmission/reception switching device 52 has terminals Pout1 and Pout2for receiving the outputs of the PA58 a and PA58 b, reception terminalsRX1 and RX2, and control terminals control1 and control2.

The signal for GSM, from the high-frequency signal processor IC 50 isput in to the PA58 a and released to the Pout1. The output of PA58 a isdetected by a coupler 54 a, and the detected signal is fed back to anautomatic output control circuit (APC circuit) 53. The APC circuit 53operates based on the detected signal to control the PA58 a.

Similarly, the signal for DCS from the high-frequency signal processorIC 50 is put in to the PA58 b and released to the Pout2. The output ofPA58 b is detected by a coupler 54 b, and the detected signal is fedback to the APC circuit 53. The APC circuit 53 operates based on thedetected signal to control the PA58 b.

The antenna transmission/reception switching device 52 has a duplexer55. The duplexer 55 has its one terminal connected to the antennaterminal, and has another two terminals connected to a GSMtransmission/reception switch 56 a and to a DCS transmission/receptionswitch 56 b.

The transmission/reception switch 56 a has its a-contact connected tothe Pout1 through a filter 57 a, and has its b-contact connected to thereception terminal RX1 through a capacitor C1. Thetransmission/reception switch 56 a is operated to select the a-contactor b-contact by a control signal received on the control terminal 1.

The transmission/reception switch 56 b has its a-contact connected tothe Pout2 through a filter 57 b, and has its b-contact connected to thereception terminal RX2 through a capacitor C2. Thetransmission/reception switch 56 b is operated to select the a-contactor b-contact by a control signal received on the control terminal 2.

A filter 60 a and low-noise amplifier (LNA) 61 a are connected in thisorder between the reception terminal RX1 and the high-frequency signalprocessor IC 50. A filter 60 b and low-noise amplifier (LNA) 61 b areconnected in this order between the reception terminal RX2 and thehigh-frequency signal processor IC 50.

This wireless communication unit performs both the GSM communication andDCS communication.

The embodiment 1 has the following effectiveness.

(1) In the high-frequency power amplifier module (hybrid integratedcircuit device), the electrode terminals 20 of LGA structure alignedalong the edges of module substrate 11 are coated in their portionsclose to the substrate edge with the protection film 40, and accordinglyeven if there arises a thermal stress between the electrode terminals 20and the module substrate 11 when the module is mounted on the setupboard 36 of portable telephone unit, the module substrate 11 isprevented from cracking in its terminal border portion close to thesubstrate edge and thus the interior of package 13 is free frompenetration of water or the like through cracks, whereby thehigh-frequency power amplifier module 10 and portable telephone unit areenhanced in reliability and life span.

(2) The protection film 40 which is made from printed paste can be asthin as several tens micrometers or less, enabling the reduction ofthickness of the module substrate and also the reduction ofmanufacturing cost owing to the reduced consumption of paste. Inconsequence, the reduction of manufacturing cost of the portabletelephone unit can be attained.

(3) The protection film 40 is formed by printing paste instead of usinga green sheet having through-holes, which enables the size reduction ofthe module substrate 11 and thus the size reduction of thehigh-frequency power amplifier module 10. In consequence, the sizereduction of the portable telephone unit can be attained.

(4) The high-frequency power amplifier module 10 is fixed to the setupboard 36 by additional use of the power voltage supply terminals 21besides the electrode terminals 20, whereby the high-frequency poweramplifier module 10 is enhanced in mount rigidity. The power voltagesupply terminals 21 also serve as ground terminals, stabilizing theground voltage in every circuit section of the high-frequency poweramplifier module 10, whereby the stable operation can be expected. Inconsequence, the portable telephone unit operates stably, enabling theuser to have comfortable communication.

(5) The power voltage supply terminals 21 are arranged along the longside and short side of the module substrate 11. On this account, thehigh-frequency power amplifier module 10 is mounted by being placeduprightly on multiple reflowing molten solder spots so that the modulesubstrate 11 is mounted by being spaced out evenly from the setup board36, whereby power supply probabilities such as efficiency can bestabilized. In consequence, the portable telephone unit operates stably,enabling the user to have comfortable communication.

(6) The module substrate 11 has the formation cut-away portions 34 atboth ends of long side, in which portions the cap 12 has its hooks 32latching with the hook stoppers 33 of the module substrate 11, therebybuilding a package, and the hook support arms 31 have their solderfillet jutting out as little as 0.3 μm. Accordingly, the mount area canbe virtually within the area defined by the profile of cap 12, enablingthe reduction of mount area. In consequence, the size reduction of theportable telephone unit can be attained.

(7) The hook support arms 31 extend downward to reach or nearly reachthe rear surface of the module substrate 11, and accordingly thehigh-frequency power amplifier module 10, when mounted on the setupboard 36 by soldering, is connected electrically by soldering to thegrounding lands 37, whereby the high-frequency power amplifier module 10is enhanced in mount rigidity and ensured in electrical grounding. Inconsequence, the portable telephone unit operates stably, enabling theuser to have comfortable communication.

(8) The provision of ground terminals at the four corners of therectangular module substrate 11 facilitates the layout design ofexternal terminals including the signal terminals and power terminals ofthe high-frequency power amplifier module 10, and it also facilitatesthe layout of wiring lines on the setup board which mounts the module10.

Embodiment 2

FIG. 18 is a schematic cross-sectional diagram of a high-frequency poweramplifier module based on another embodiment (embodiment 2) of thisinvention. FIG. 19 is a plan view of the bottom of the module substrateof the high-frequency power amplifier module. FIG. 20 is across-sectional diagram showing partially the connection of an electrodeterminal to the setup board of the high-frequency power amplifiermodule.

In this example of the embodiment 2, a protection film 40 is coatedaround the whole rim of the electrode terminals 20 and power voltagesupply terminals 21 as shown in FIG. 18, FIG. 19 and FIG. 20. Theembodiment 2 has the same effectiveness as the embodiment 1.

Embodiment 3

FIG. 21 is a plan view of the bottom of a high-frequency power amplifiermodule based on still another embodiment (embodiment 3) of thisinvention. In this example of the embodiment 3, hook stoppers 33 aredisposed at the middle of the sides of the module substrate 11. Incorrespondence to these hook stoppers 33, the cap 12 has its hooksupport arms 31 (not shown) located at the middle of the sides of thecap 12. In the embodiment 3, the foot print on the terminal side can beconnected without jutting out of the module substrate, allowing theuser's circuit board to have an increased setup area.

Embodiment 4

FIG. 22 is a perspective view of a high-frequency power amplifier modulebased on still another embodiment (embodiment 4) of this invention, andFIG. 23 is-a cross-sectional diagram of the hook/stopper section of themodule substrate 11 and cap 12. In the embodiment 4, the modulesubstrate 11 has, on its 36 two confronting sides, cut-away portions 80,and the cap 12 has lugs 81 to latch with the substrate cut-awayportions. The cap 12 is put on the module substrate 11, and the lugs 81and cut-away portions are coupled and fixed by solder 82.

According to the embodiment 4, when the caps are soldered to thesubstrate before it is diced, unsuccessful division due to erroneoussoldering which bridges between adjacent caps can virtually be avoided.

Although the present invention has been described in connection with thespecific embodiments, the invention is not confined to theseembodiments, but various alterations are obviously possible withoutdeparting from the essence of the invention. For example, the foregoingembodiments are high-frequency power amplifier modules as hybridintegrated circuit device, the present invention is applicable to otherhybrid integrated circuit devices and electronic devices whichincorporate these devices. For example, the present invention can alsobe applied to the voltage-controlled oscillator (VCO) and antenna switchamong the circuit devices used in portable telephone units.

Although the semiconductor amplifying elements used for the amplifyingstages of the embodiment 1 are MOS (Metal Oxide Semiconductor) FETs,these elements may be replaced with transistors of other types such assilicon bipolar transistors, GaAs-MES (Metal-Semiconductor) FETs, HBT(Hetero Junction Bipolar Transistors), HEMT (High Electron MobilityTransistors), and Si—Ge FETs.

INDUSTRIAL APPLICABILITY

As described above, the inventive hybrid integrated circuit device isused by being incorporated as a high-frequency power amplifier modulewhich is used in the transmitter of wireless communication units such ascellular telephone units. Particularly, the inventive high-frequencypower amplifier module has its module substrate-reinforced in theportion close to the substrate edge by the coating of a protection film,whereby the occurrence of substrate cracking at the time of modulemounting can be alleviated and the reliability of module mounting can beenhanced.

1-38. (canceled)
 39. A power amplifier module having a power amplifyingcircuit, comprising: a first wiring substrate having a main surface anda back surface which is opposite to the main surface; a semiconductorchip having an amplifying element of the power amplifying circuit,mounted over the main surface of the first wiring substrate; a pluralityof first electrode terminals arranged over the back surface of the firstwiring substrate; a plurality of second electrode terminals arrangedover the back surface of the first substrate; wherein a land grid arraystructure comprises the first and second electrode terminals; theplurality of the first electrode terminals are used for inputting andoutputting of signals for the power amplifying circuit; the plurality ofthe second electrode terminals are used for a power supply; the firstwiring substrate has two pairs of edges opposing each other in a planview; the plurality of the first electrode terminals are arranged alongthe two pairs of edges of the back surface of the first wiringsubstrate; the plurality of the second electrode terminals are arrangedinside the plurality of the first electrode terminals in the backsurface of the first wiring substrate; and the second electrodeterminals are not disposed at the two pairs of edges of the back surfaceof the first wiring substrate.
 40. A power amplifier module according toclaim 39, wherein the power amplifier module is to be mounted on a mainsurface of a second wiring substrate; wherein a plurality of lands aredisposed on the a main surface of the second wiring substrate; the firstand second electrode terminals of the first wiring substrate areconnected with the plurality of lands of the second wiring substrate viasolder.
 41. A power amplifier module according to claim 39, wherein theplurality of second electrode terminals are arranged in rows.
 42. Apower amplifier module according to claim 39, wherein the poweramplifier module is employed in a mobile communication unit.
 43. A poweramplifier module according to claim 42, wherein the power amplifiermodule has a plurality of amplifying systems.
 44. A power amplifiermodule according to claim 43, wherein the plurality of amplifyingsystems include a GSM system and a DCS system.
 45. A power amplifiermodule according to claim 39, wherein the first wiring substrate iscomprised of a ceramic.
 46. A power amplifier module according to claim39, wherein the amplifying element in the semiconductor chip iscomprised of a MOSFET.
 47. A power amplifier module according to claim39, wherein the semiconductor chip is covered by an insulative resin.48. A power amplifier module according to claim 39, wherein a capacitorelement or a resistor element are mounted over the main surface of thefirst wiring substrate.